The invention relates to a method of washing clothes using a washing machine having a washing tub which has a fixed drum and a movable drum.
Conventional washing machines generally accomplish washing action by establishing a vortex flow within a washing tub to repeatedly agitate clothes by drawing them into the tub of the machine. In such a machine, the volume of the tub must be large with respect to the amount of clothes being washed. In the case that a small load of clothes is being washed, the vortex flow is so hard that the clothes are washed excessively. On the other hand, if a large load of clothes is put into the machine, the resulting vortex flow is too slow and insufficient to efficiently wash the clothes. Moreover, since only a portion of the clothes will accidentally contact the agitator, it is unlikely that all of the clothes will be washed thoroughly by the effect of twisting of the clothes within the washing tub. Conversely, the portion of the clothes which does contact the agitator is washed excessively, so that such articles may be damaged within the washing tub.
Recently, a new type of washing machine is available. This type of washing machine does not have an agitator but has a washing tub which is horizontally rotatable as a whole with washing liquid and clothing mixed therein for washing. The tub is intermittently rotated in forward and reverse directions to wash the clothes by means of a vortex flow produced by the difference in flow speed between the washing liquid and the articles of clothing. In this type of washing machine the clothes are not damaged. Examples of such teachings are shown in Japanese Publications Nos. 49-33863 and 51-56580 and in U.S. Pat. No. 2,986,916. Another example of a simple rotating drum is shown in Japanese Publication No. 36-13469. However, this new type of washing machine has relatively low washing power because the difference in flow speed between the clothes and the liquid stored within the washing tub is small. Accordingly, many conventional washing machines fail to provide an equivalent and homogeneous wash with varying amounts of clothes in the machine.